My interest is on studying the dynamics of the Bay of Bengal and Arabian Sea using in-situ, satellite and model outputs. Supervisors: Dr. R. Venkatesan, Dr. G. Latha, Dr. Usha Natesan
Warming of the northern Bay of Bengal during late southwest monsoon was very much influenced by t... more Warming of the northern Bay of Bengal during late southwest monsoon was very much influenced by the intensity of freshening by river discharges. The inter-annual variability of freshening and associated warming was analyzed for 2011 to 2015, with the help of in-situ data obtained from the moored buoys deployed at specific locations in northern Bay of Bengal. The shoaling of mixed layer depth associated with the advection of freshwaters has favored intense warming and supported convective activity thereby. The year 2011 recorded highest freshening with salinity touched as low as 21.3 p.s.u.; with the heavy river discharges, resulted from intense rainfall over catchment areas of rivers that discharged into the bay, due to positive Indian Ocean Dipole and La-Nina affect. It has resulted in intense warming of the surface temperature by 2°C, which persisted for nearly three weeks. The year 2014 was least fresh, with no signature of freshening and associated warming. The latent heat flux term computed from the moored buoy using the COARE 3.5 algorithm showed increased loss of latent heat flux during the late monsoon associated with the warming. It directly supported increased convective activity and delayed the withdrawal of monsoon activity from Indian sub-continent. Two depressions with intense convective activity formed over bay during September of 2011 which delayed the withdrawal of monsoon by three weeks.
A continuous data on the surface meteorological, surface and subsurface data on temperature, sali... more A continuous data on the surface meteorological, surface and subsurface data on temperature, salinity and current is available online with the deployment of twelve moored buoys; Ocean Moored Network for the Northern Indian Ocean (OMNI) with seven buoys in the Bay of Bengal and five in the Arabian Sea. This network of OMNI buoys has been providing data which are of great relevance to the climate research community to constantly monitor the seasonal, intra-seasonal, annual and inter-annual variations in the northern Indian Ocean. In the long run the data accuracy is another important part of the program, to ensure the quality of the data delivered from these buoys, especially for the sub-surface data where satellite cannot reach. Conductivity-Temperature-Depth profile is done adjacent to the buoy locations during various phases of service of the buoys. This operation carried out in three phases in the Bay of Bengal has been compared with the buoy data, in order to ensure the quality o...
The moored buoy network deployed in the Bay of Bengal played a critical role in the collection an... more The moored buoy network deployed in the Bay of Bengal played a critical role in the collection and transmission of surface meteorological and oceanographic conditions in real time through satellite telemetry, enabling constant monitoring of the cyclone Phailin. It is the first report of in situ timeseries measurement of a very low pressure taken during cyclones in the northern Indian Ocean. The BD10 buoy recorded a minimum atmospheric pressure of 920 hPa, which happened to be within the eye of the cyclone. This article presents an account of important changes that were observed in the surface meteorological and oceanographic parameters under the influence of the very severe cyclonic storm Phailin. An attempt has been made to understand the role of stratification in intensifying the cyclone Phailin in comparison with the cyclone Lehar which weakened in the ocean itself, based on subsurface data from the moored buoys which were on the track of the respective cyclones. Both the cyclone...
A continuous data on the surface meteorological, surface and subsurface data on temperature, sali... more A continuous data on the surface meteorological, surface and subsurface data on temperature, salinity and current is available online with the deployment of twelve moored buoys; Ocean Moored Network for the Northern Indian Ocean (OMNI) with seven buoys in the Bay of Bengal and five in the Arabian Sea. This network of OMNI buoys has been providing data which are of great relevance to the climate research community to constantly monitor the seasonal, intra-seasonal, annual and inter-annual variations in the northern Indian Ocean. In the long run the data accuracy is another important part of the program, to ensure the quality of the data delivered from these buoys, especially for the sub-surface data where satellite cannot reach. Conductivity-Temperature-Depth profile is done adjacent to the buoy locations during various phases of service of the buoys. This operation carried out in three phases in the Bay of Bengal has been compared with the buoy data, in order to ensure the quality of the conductivity-temperature measurements taken by the OMNI buoys. The high correlation between both the data sets ensures the quality of the data delivered by the Conductivity-Temperature sensors attached along the mooring line of the OMNI buoys.
The moored buoy network deployed in the Bay of Bengal played a critical role in the collection an... more The moored buoy network deployed in the Bay of Bengal played a critical role in the collection and transmission of surface meteorological and oceanographic conditions in real time through satellite telemetry, enabling constant monitoring of the Phailin cyclone. It is a first report of in-situ time series measurement of a very low pressure taken during cyclones in the northern Indian Ocean. The BD10 buoy recorded a minimum atmospheric pressure of 920hPa which happened to be within the eye of the cyclone. The paper presents an account of important changes that were observed in the surface meteorological and oceanographic parameters under the influence of the very severe cyclonic storm Phailin. An attempt has been made to understand the role of stratification in intensifying the Phailin cyclone in comparison with the Lehar cyclone which weakened in the ocean itself based on the sub-surface data from the moored buoys which happened to be on the track of the respective cyclone. Both the cyclones traversed across the BoB in a similar way and the buoys which happened to be very close to the cyclone track withstood the rough sea conditions during the storms with its specially designed body. The BD09 buoy which happened to be on the right side of the Phailin cyclone track moved in a circular path as a result of the inertial oscillation forced by the strong cyclonic winds.
Warming of the northern Bay of Bengal during late southwest monsoon was very much influenced by t... more Warming of the northern Bay of Bengal during late southwest monsoon was very much influenced by the intensity of freshening by river discharges. The inter-annual variability of freshening and associated warming was analyzed for 2011 to 2015, with the help of in-situ data obtained from the moored buoys deployed at specific locations in northern Bay of Bengal. The shoaling of mixed layer depth associated with the advection of freshwaters has favored intense warming and supported convective activity thereby. The year 2011 recorded highest freshening with salinity touched as low as 21.3 p.s.u.; with the heavy river discharges, resulted from intense rainfall over catchment areas of rivers that discharged into the bay, due to positive Indian Ocean Dipole and La-Nina affect. It has resulted in intense warming of the surface temperature by 2°C, which persisted for nearly three weeks. The year 2014 was least fresh, with no signature of freshening and associated warming. The latent heat flux term computed from the moored buoy using the COARE 3.5 algorithm showed increased loss of latent heat flux during the late monsoon associated with the warming. It directly supported increased convective activity and delayed the withdrawal of monsoon activity from Indian sub-continent. Two depressions with intense convective activity formed over bay during September of 2011 which delayed the withdrawal of monsoon by three weeks.
A continuous data on the surface meteorological, surface and subsurface data on temperature, sali... more A continuous data on the surface meteorological, surface and subsurface data on temperature, salinity and current is available online with the deployment of twelve moored buoys; Ocean Moored Network for the Northern Indian Ocean (OMNI) with seven buoys in the Bay of Bengal and five in the Arabian Sea. This network of OMNI buoys has been providing data which are of great relevance to the climate research community to constantly monitor the seasonal, intra-seasonal, annual and inter-annual variations in the northern Indian Ocean. In the long run the data accuracy is another important part of the program, to ensure the quality of the data delivered from these buoys, especially for the sub-surface data where satellite cannot reach. Conductivity-Temperature-Depth profile is done adjacent to the buoy locations during various phases of service of the buoys. This operation carried out in three phases in the Bay of Bengal has been compared with the buoy data, in order to ensure the quality o...
The moored buoy network deployed in the Bay of Bengal played a critical role in the collection an... more The moored buoy network deployed in the Bay of Bengal played a critical role in the collection and transmission of surface meteorological and oceanographic conditions in real time through satellite telemetry, enabling constant monitoring of the cyclone Phailin. It is the first report of in situ timeseries measurement of a very low pressure taken during cyclones in the northern Indian Ocean. The BD10 buoy recorded a minimum atmospheric pressure of 920 hPa, which happened to be within the eye of the cyclone. This article presents an account of important changes that were observed in the surface meteorological and oceanographic parameters under the influence of the very severe cyclonic storm Phailin. An attempt has been made to understand the role of stratification in intensifying the cyclone Phailin in comparison with the cyclone Lehar which weakened in the ocean itself, based on subsurface data from the moored buoys which were on the track of the respective cyclones. Both the cyclone...
A continuous data on the surface meteorological, surface and subsurface data on temperature, sali... more A continuous data on the surface meteorological, surface and subsurface data on temperature, salinity and current is available online with the deployment of twelve moored buoys; Ocean Moored Network for the Northern Indian Ocean (OMNI) with seven buoys in the Bay of Bengal and five in the Arabian Sea. This network of OMNI buoys has been providing data which are of great relevance to the climate research community to constantly monitor the seasonal, intra-seasonal, annual and inter-annual variations in the northern Indian Ocean. In the long run the data accuracy is another important part of the program, to ensure the quality of the data delivered from these buoys, especially for the sub-surface data where satellite cannot reach. Conductivity-Temperature-Depth profile is done adjacent to the buoy locations during various phases of service of the buoys. This operation carried out in three phases in the Bay of Bengal has been compared with the buoy data, in order to ensure the quality of the conductivity-temperature measurements taken by the OMNI buoys. The high correlation between both the data sets ensures the quality of the data delivered by the Conductivity-Temperature sensors attached along the mooring line of the OMNI buoys.
The moored buoy network deployed in the Bay of Bengal played a critical role in the collection an... more The moored buoy network deployed in the Bay of Bengal played a critical role in the collection and transmission of surface meteorological and oceanographic conditions in real time through satellite telemetry, enabling constant monitoring of the Phailin cyclone. It is a first report of in-situ time series measurement of a very low pressure taken during cyclones in the northern Indian Ocean. The BD10 buoy recorded a minimum atmospheric pressure of 920hPa which happened to be within the eye of the cyclone. The paper presents an account of important changes that were observed in the surface meteorological and oceanographic parameters under the influence of the very severe cyclonic storm Phailin. An attempt has been made to understand the role of stratification in intensifying the Phailin cyclone in comparison with the Lehar cyclone which weakened in the ocean itself based on the sub-surface data from the moored buoys which happened to be on the track of the respective cyclone. Both the cyclones traversed across the BoB in a similar way and the buoys which happened to be very close to the cyclone track withstood the rough sea conditions during the storms with its specially designed body. The BD09 buoy which happened to be on the right side of the Phailin cyclone track moved in a circular path as a result of the inertial oscillation forced by the strong cyclonic winds.
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Papers by Simi Mathew